Radiation sources made from semiconductor material are available which emit IR radiation from an active area consisting of A3B5 material and a p-n junction. The source is constructed on the basis of an n-InGaAs/p-InGaAs/n-InAs heterostructure and emits radiation of a wavelength in the range 2.5-4 μm. Typically such sources are used to measure the transmittance of a gas mixture in the hydrocarbon absorption band area of 3.3 μm. Such sources have a long lifetime (more than 30,000 hours) and a narrow spectrum of radiation (less than 0.4 μm), both of which allow these sources to be used in gas analysis equipment. However, these sources cannot work at temperatures above 80° C. Furthermore, these sources (sources with narrow band substrate) have top wire bonding, as a result of which it is difficult to incorporate them with fibres.
Other semiconductor sources of IR radiation are known which emit radiation in the near IR spectral range of the spectrum, i.e. around 1-2.5 μm, and are able to work at increased temperatures. However, the emitted wavelength is of limited usefulness.
The present invention aims to provide an improved radiation source for emission of IR radiation.